Printer control system and method for changing print mask height

Abstract

A system and a method for improving the quality of prints using a print mask for a printer with at least one printhead with a plurality of dot forming elements arranged in dot forming element sections, and at least one of the masks are altered so that mask data corresponding to at least one complementary set of dot forming elements is activated or deactivated in response to the paper location and the dot forming element section is shifted as the printhead passes a transition position. As the mask size is reduced, for example, the mask contents are shifted to one end of the printhead. This remapping of the mask within the head allows the page advance distance to be changed to the new page advance distance only once.

1. A method for printing an image using a printer including a paper path having a transition position as paper is advanced in a page advance direction, and including a printhead having a plurality of dot forming elements, the method comprising the steps of:
 a. providing a print mask for printing in a first print mode with a first number of the plurality of dot forming elements, the print mask including mask data arranged in mask sections corresponding to sets of complimentary dot forming elements; 
 b. printing a portion of the image with the first number of the plurality of dot forming elements in the first print mode using the print mask; 
 c. switching to a subsampled print mask for a second print mode as the paper is advanced past the transition position near a trailing edge of the paper, the switching step including: 
 i) decreasing the mask size by deactivating every Nth set of mask data from each mask section corresponding to complementary dot forming elements; and 
 ii) shifting mask data in a same direction as the page advance direction; and 
 d. printing a portion of the image near the trailing edge of the paper with the subsampled print mask corresponding to a second number of the plurality of dot forming elements, such that the second number is less than the first number. 
 
     
     
       2. The method according to  claim 1 , wherein a mask edge stays in a same place relative to the printhead. 
     
     
       3. The method according to  claim 1 , wherein dot forming operational malfunction is considered in order to determine which mask data is deactivated. 
     
     
       4. The method according to  claim 3 , wherein a height of the print mask is adjusted in order to change the pattern of complementary nozzles. 
     
     
       5. The method according to  claim 1 , wherein the decreasing step is performed sequentially, one mask section at a time. 
     
     
       6. The method according to  claim 5  wherein a first advance distance is changed to a second advance distance at the transition position so that a mask edge stays at a same position relative to a paper edge.